A forklift includes a hydraulic driving apparatus called hydro static transmission (HST) provided between an engine, or a driving source, and driving wheels. The HST includes, in a closed main hydraulic circuit thereof, a travel hydraulic pump which is a variable displacement pump driven by the engine and a hydraulic motor which is a variable displacement motor driven with working fluid discharged from the travel hydraulic pump. The vehicle travels by the driving force of the hydraulic motor transmitted to the driving wheel. An engine controlling apparatus of a forklift including the HST is described in Patent Literature 1.